Electric heating device.



W. S. HADAWAY, JR.

ELECTRIC HEATING DEVICE.

APPLICATION FILED SEPT. 5. 1911.

1,157,100. Patented Oct. 19, 1915.

2 SHEETS-SHEET I.

w. SQHADAWAY, JR.

ELECTRIC HEATING DEVICE.

APPLICATION FILED SEPT. 5. 1911,

Patented Oct. I9, 1915.

2 SHEETS SHEEI 2 WZZZZWZS Eadawf: 3a

WILLIAM S. HADAWAY, .13., OF NEW YORK, N. Y.

ELECTRIC HEATING DEVICE.

in? MM.

Appiication flied September 51811.

a known that l, \YiLLrAM S. HAMWAY, tizen of the United States, residinglzoriif. in the county of New York and mate of New Yorli have in. entednew and fni improvements in l....i-ctrie Heating ilk-vices, of which the'ioilow ing is a full,

7 concise, and exact dose! hei had to tile a ing. forming a part of nsspeeirn My invention relates to electric devices it has among it: oiprovide an eirctri: hcah in an. of heat by radiation is it down. to theminimum, and if h the heat iil ecteiil to the surface to 3 may n"rtgalatcd to any desired heating My im'entmn further has aiming its ob-5 to provide an nuproved heater, where parts are cmzepactl v assembledand "ling cienirnt may be made up into ages at my im-- ereina tierappear.

i have for 1 my invenarmer. oi' oi choco- I shall i to this use. imitcdin the spciific l.

a in: I

the type used in tin.

lav

: l iguic l si-mbled sho 's a inverted I, exposed. sertional view shownin Fig. .tioiisl view on "mm a detail clung; the conzit. Figs. 5. T. 8,:ir'mms the heater. In tin: 11 mm in these figures, the chocoiatc heaterwind of three pans. A. ii and formed of h l'ilv tinned plate L znilarcon for This. is saint 11 Ar is prof- 12 in a suitable.

line i i Vim" (it (lw tor; and

which oi .i enin tm'ai,

i. within.

5 with! i Kr sti Specification of L tters Patent.

Serial No. 647,692.

heating element and Will be more full hereinafter described, is carriedwithin t e pan A, as shown in Figs. 1 and 3, so that an air space isformed between the outer surface of the pan B and the inner surface ofthe pan A. These surfaces are preferably iighly polished.

In the form illustrated, the upper edges of the pans A and B areprovided with Elan 2 and 3, which are soldered together, so that thesepans may be inserted in an opening in a table, as a single device. Thepan (J which holds the material to be heated is carried Within the panB, as shown in *ig. 3, and is provided With suitable flanges 4 and 5, onits sides, which are adapted to receive marble slabs upon which theoperators work. As illustrated in F ig. 3, the pan (.7 rests upon theflanges 3 of the pan B, and

l and 5 of the pan C, so as to hold the parts of the device in position.The pan C is provided with suitable handles 7 at its ends, so that whenthe slabs 6 are pushed back, it may be readily removed for cleaning orother purposes.

The pin B, containing the heating element, is shown in Fig. 2, withthe'heating clement exposed. As shown in this figure and in Fig 3, thispan is provided with an inner rounded bottom plate 8, preferablyiflililP-l integral with the flange 3. Over this rounded bottom isplaced a sheet 9 of insulating material. If desired asbestos may heused. Over this sheet of insulation is placed a sheet of insulatingmaterial 10, carrying upon its surface the resistance matcrial Ill. In apreferred form I use a sheet of mica as the insulating materia Over thisresistance material is placed a sheet of insulation 12, which may beformed of asbestos and over this sheet 12, is placed a sheet 13 of ahighly polished metal, such as tinned plate. The edges of the varioussheets may be secured to the bottom 8, in any suitable way. Forinstance, as shown in big. 2, I may hold these edges in pa sition bymeans of strips 15, which are slightly spaced from the plate 8 so thatthe edges of the sheets may be slipped between the sillllk tlll l saidplate. These strips extend along beneath the flanges 3, and are bent attheir ends to extend around the square ends of the pan.

Upon the ends 16, of the pan, are carried strips 1?. suitably fixed tothe ends and ratented Oct. 19, 1915.

adapted to receive the bent ends of the strips 15. The ends i8 of thestrip 17, are adapted to he bent over upon the strips 15, as shown inFig. 2. In the form shown, both of the edges of the strips 9 and 10 areheld in position by this means and the sheets 12 and 13 are then bentover to conform to the rounded surface of the bottom of the pan end areheld close upon the resistance innteriahhy suitable hands 19 and 20,suitably fixed to the strips 17) near the opposite ends of the pen. In apreferred form, the hands 19 and ii are proiidcd with interfitting ends,so they may look together and hold. the sheets 12 and. 13 firmiy uponthe resistance materiel. As illustrated in Fig. 2, the strips 26, may heprovided with ears 21, and the strips 19 may he slotted, as at 22, toreceive these ton ces.

From toe foregoing description it is evident that the blight surfacedcarrier 13 performs the dual function of supporting the resistor firmlyin contactwith the snrface to he heated, thus producing more eilic' mconductivity of heat thereto and oh mining he'tter surface distributionof the heat and. by reason of the proper ies of polished surfaces asregards heat trevei. aiding in making the heat. insulation more eil'ectivc.

As illustrate? in. the resistance element proper consists of a suitablesheet of insulating material 10, upon which the re sistence nmtcriai iscarried. In a preferred form, I employ 2: sheet of mice, since I findthat this material is able to withstand the temperatures to which such:1. device is sub jected, and may he ohtained in extraordinarily thinsheets, being at the same time ieihle and Capable of being bent into any(issued shape. In a preferred form, I cover the sheet of 3-12: with thincoating of shellac. in this figure, ti lil'Shii HW'I? is preferablycarried upon surface o the sheet 1G. 1t oln his 1" -:-1 tsncc nietci'ieimay he of my In e preferred nc'm. ii wpl'g a resistance may torizii oi"UH. relies s f i wire i c mvoiutions acr ss the sh This ri c ed wirewound hack and forth across the sheet in substantially parallel rows.and at tin" edges of the sheet is passed. hetweci'i notches L3. Thesenotches :ir'c pref rehl v fm'nied of varying depths, and as shown in Fig2 may be arranged alternately in several series. two short notches beinginnnedieteiy between two long notches. The re'llexeiii wire is wound inl\(?i,.\'i8!i these notches on the opposite edges of the sheet, one ofthe cimvolutions passing to a short n it-h end then across on the backof the sheet to the next-short notch, while the other convolution passesbetween the two long noteheswvhich are between the two short notches,just mentioned. Any suitable circuit connections may be made for theresistance element; but in a preferred form, I form this element of twosections, so that it may be connected either in. series, or in parallel,to vary the heat as desired.

One method of connecting the unit is clearly shown in Figs. 6, 7, 8 and9. As shown in these figures, two sections of re sistance wire 24 and'25, are arranged in parallel, and are connected with a lead 26, betweenthe brzn'ichcs of the circuit, and lends 27 and leading otf from thelirmi-cncs 24 am In a preferred form, a series-parallel switch 29, ofany desired construction, illustrated diagrammatically in these figures,is connected in circuit in the lead 26., and is adapted to change theconnections of the leads :26, 27 and For ilr' stance, when it is desiredto use the maximum heat from the heater the sections and 25 of theresistance are placed in pan aliel, as shown in Fig. t, the currentpassing through one side of the switch 29 to the conductor 26 and thendividing and passing in parallel through the two branches 24. and Q5 ofthe heating element to the other side of the iine. When it is desired toprovide a medium heat, the circuit connections are preferably thoseshown in Fig. 7, wherein one of the sections of resistance is cut out,the circuit extending through the conductor '27, to the section 24:, andthen through the conductor 26 and the switch 29 to the opposite side ofthe line. "When a still lower heat desired, the connections are thoseshown in Fig. wherein the current passes through the conductor 2 to theresistance section 24, resistance section 25), the conductor :28, andthe switch 29 to the opposite side of the line. When it is desired tocut out ihe heater, the circuit connections are referoly those shown inFig. 9, wherein t. e ter niinols of the switch are not bridged and thecircuit opened. It is evident, however, that these circuit connectionshereinahove desovihed may he changed if desired.

The conductors 26, 27 and 28 are attached to the resistance wire, asshown in Figs. 2 and 5, the ends of the conductors passing fin-or hsuitable perforations 30, in one edge of the sheet 12: the conductor 26being connected to the end of :1 convolution at one end of theresistance element, while the two conductors 27 and .2-8, are connectedat the other end to the ends of adjacent convoiutions. The sheet 13, isprovided with av suitable slot or cutaway portion 31, to rniit thepassage of the conductors 2'? an 538 through the same. As shown in Fig.5, the conductors may he attached to the ends of the refiexcd wires, bypassing the ends of the conductors through suitable perforations 32, inthe sheet 10, and binding the ends of the conductors to this sheet, byturning the ends reflexed resistance wire wound in convolutions upon aninsulating base, and means for reflecting the heat waves generated bysaid unit and confining the same within the outer receptacle.

6. In an electric chocolate Warmer, an outer pan having a curved bottom,an inner chocolate pan arranged to extend into said outer pan and havinga bottom of the same configuration as the bottom of said outer pan, anda heating pan intermediate said pans and of the same configuration assaid pans, said heating pan including a heating unit of refiexedresistance wire wound upon an insulating base and inclosed betweensheets oi insulation.

7. In an electric chocolate warmer, an outer pan having a curved bottom,aninner chocolate pan arranged to extend into said outer pan and havinga bottom of the same configuration as the bottom of said outer pan, aheating pan intermediate said pans and of the same configuration as saidpans, said heating pan including a heating unit of reflexed resistancewire wound upon an insulating base, and means for reflecting the heatwaves generated by said-heating unit and retaining the same within saidpans.

8. An electric heating pan for chocolate warmers, comprising a metallicpan, a heating unit therefor including a resistance wire carried upon aninsulating base and inclosed between sheets of insulation, and means forholding said heating unit against one of the surfaces of said pansincluding an outer polished metallic srieet and transversely extendingbands.

9. An electric heating pan for chocolate warmers, comprising a metallicpan, a heating unit therefor including a reflexed resistance wire woundin convolutions upon an insulating base and inclosed between sheets ofinsulation, and means including a metal sheet having a highly polishedouter surface and transversely extending bands for holding said heatingunit against the surface of said pan.

10. An electric heating pan for chocolate warmers, comprising a metallicpan, a heating unit therefor including a. resistance material carriedupon an insulating base and inclosed between sheets of insulation, andmeans for compressing said unit against one of the surfaces of said panincluding an outer metal sheet having a highly polished outer surfaceand transversely extending interfitting bands carried by said pan.

11. In an electric heating pan for chocolate warmers, a metallic pan, aheating unit therefor including a rellexed resistance wire wound inconvolutions upon a mica base and inclosed between sheets of asbestos,and means including an outer metallic plate for holding the unit againstone of the surfaces of said pan.

late warmers, a

12. In an electric heating pan for chocolate warmers, a metallic panhaving a curved bottom, a heating unit therefor including a reflexedresistance wire wound upon a flexible insulating base and inolosedbetween sheets of insulation, and means for holding said heating unitsnugly against the curved bottom of said pan, including an outer metalplate and transversely extending bands.

13. In an electric heating pan for chocomctallic pan having a curvedbottom, a heating unit formed of convolutions of reflexed resistancewire, wound on an insulating base, sheets of insulation on both. sidesof said heating unit, and means including an outer sheet for clampingsaid resistance unit and the sheets of insulation snugly against thecurved surface of said pan.

14. In an electric heating pan for choco late warmers, a metallic pan, aheating unit therefor including a retlexed resistance wir wound inconvolutions on a shellac covered mica base, and inclosed between sheetsof asbestos, means for holding said unit against one of the surfaces ofsaid pan including an outer metallic plate and transversely extendingbands fixed to said pan, and means for permitting electrical connectionsto be made to said resistance material.

15. In an electric heating pan for chocolate warmers, a metallic pan, aheating unit therefor and means for holding the same against one of thesurfaces of said pan in cluding a plurality of transversely extendingbands, and a removable support for said bands carried by said pan.

16. In an electric heating pan for chocolate warmers, a metallic pan, aheating unit therefor including a resistance material wound upon aninsulating base and inclosed between sheets of insulation, means forcompressing said resistance unit against one or the surfaces of said panincluding anouter metallic sheet and transversely extending bands, andremovable supports for said bands carried by saidpan.

17. In an electric chocolate warmer, the combination of a chocolate pan,an outer pan into which said chocolate pan extends, an electric heatingpan between said chocolate pan and said outer pan, and means forreflecting the heat waves generated by said heating unit.

18. In an electric chocolate warmer, the combination of a chocolate panhaving a curved bottom, an outer pan having a similar bottom andarranged to receive said chocolate pan, a heating pan arranged to bereceived between said chocolate pan and said outer pan, and means forreflecting the heat waves generated by said heating pan and retainingthe same within said pans.

19. In an electric chocolate warmer, the

combination of a plurality of nested pans having curved bottoms, aheating pan having a similarly shaped bottom, fitted between said pans,means for varying the heat generated by said heating pan as desired,electrical terminal connections carried by said outer pan, and means forretaining within said pans the heat generated by said heatin pan.

20. ii an electric chocolate warmer, the combination of a chocolate pan,an outer inclosing pan, a heating pan nested between said previouslymentioned pans, means for graduating the heat generated by said heatingpan as desired, and means including highly polished surfaces on certainof said pans for reflecting the heat generated by said heating pan andretaining the same within said pans.

21. In an electric chocolate Warmer, the combination of an electricallyheated receptaclej for containing chocolate and inaintairr ing it inheated condition, an electrically heated-fiat side pan adjacent thereto,and a flange or apron on said receptacle overlying the edge of the sidepan for preventing leakage during the transfer of chocolate from thereceptacle to the side pan.

' 22. In a device of the class described, an electrically heated vesselfor maintaining the contents in heated condition, said vessel having anapproximately cylindrical bottom and having one of its upper edgessubstantially horizontal and rectilinear, an electrically heatedsubstantially fiat side pan whereon the material from the vessel may bemanipulated by the operator, and interfitting connections between oneedge of the side pan and said rectilinear edge of said vessel to therebyprevent leakage during transfer of said material from the vessel to theside pan.

23. In an electric heating device, a receptacle having a convex outersurface, a heating element, and a bright surfaced carrier side of saidresistor and means for holding said metallic sheet close against saidresistor, for the purpose described, said resistor being suitablyinsulated from said receptacle and from said metallic sheet.

25. In combination, a receptacle having a cylindrical bottom, insulatingmaterialadjacent thereto, an electric heating element adjacent to saidinsulating material, outer insulating material adjacent to said heatingelement on the outside thereof and a sheet of polished metal outside ofsaid outer insulating material holding the parts within in close contactwith each other.

26. In combination, a metallic receptacle having a bottom which isconvex on the outside, a plurality of laye s of insulating materialoutside of the bottom of said receptacle, a resistor interposed betweentwo of said layers and a sheet of bright tin holding the parts mentionedin close contact with each other to thereby perform the dual function ofsupporting the resistor and its insulation and minimizing the heat loss.

27. A warmer comprising a metallic receptacle having a rounded bottom, arefleXed resistor external thereto, insulation outside 1 of saidresistor, and a metallic sheet, bright inside and out, pressing saidinsulation toward said receptacle.

In witness whereof, I have hereunto subscribed my name in the presenceof two Wit-

